ppelosi@hotmail.com

Department of Surgical Sciences

and Integrated Diagnostics (DISC)

IRCCS San Martino IST

University of Genoa, Genoa, Italy

Hemodynamics and

Mechanical Ventilation

Paolo Pelosi

Conflicts of Interest

I declare

NO conflicts of interest

Determinants of Cardiac Output

What should we know for txdecisions ?

• Preload

• Flow

• Flow adequacy

Fluids

Inotrops

Pressors dilators

Treatment !

Preload & Stroke Volume

PRELOAD = RVEDV/LVEDV

(Frank-Starling)

RAP/CVP IS A FUNCTION OF

FOUR INDIPENDENT

PARAMETERS

• Blood volume and flow in the central

veins

• Right ventricular compliance and

contractility during diastolic filling

• Central veins tonus

• Ventricular interactions

• Intrathoracic pressure

• Patient’s posture

• Venus obstruction

• Valvular alterations (stenosis/tricuspidal

insufficiency) and ventricular compliance

• Cardiac rythm and respiratory rate

…….RAP/CVP IS A FUNCTION

OF MANY OTHER FACTORS

HEARTITP

THORAX

V

CAO

RV LV

VENOUS RETURN CURVE

PmS - RAP VR = --------------------

r

Pms

Rap

0

1

2

-4 -2 0 2 4 6 7

Right Atrial Pressure

Ven

ou

s R

etu

rn

P2P1

PAWP

• PAWP LAP - shape(eccentric) of the balloon

- no zone III West

- venous pulmonary occlusion

• LAP LVEDP- stenosis or insufficiency of the mitral valve- tachicardia and premature occlusion of mitral valve- atrial contraction during hypovolemia

• LVEDP LVEDV Compliance variations due to:

- Stiffness of LV

- Pressure around pericardium (effusion, ITP)

- Ventricular interdependence

ZONE_WEST_

1 PA>Pa>Pv_

2 Pa>PA>Pv_

3 Pa>Pv>PA_

• Use transmural filling

pressures !

• CVPTM = CVP - IAP/2

• PAOPTM = PAOP - IAP/2

ITP

CVP PAOP

IAP

Intensive Care Med 2007; 33(1): 6-8

CO determinants

CO

Preload = RVEDV/LVEDV

Afterload

ContractilityFrequency

Intra Thoracic Blood Volume:preload?

ITBV TBV

ITBV

3=

ECHO

Esophageal Doppler

LiDCO

Picco

Vigileo

By the Nepean Institute of Critical Care Education and Research

Vieillard-Baron et al

AJRCCM 168:1270;2003

CO can be preserved even when EF is markedly altered

CO can be altered even when EF is normal (hypovolemia)

CO

PAC PICCO LIDCO*

OEDECHO FICKNICO

Vigileo

Nonivasive

Invasive

SV = VTI x LVOTare a

Me asu re m e n t o f card iac o u tp u t

LVOT=

left ventricular outflow tract

VTI= velocity time integral

Apical 5 chambers

PARASTERNAL LONG AXISMeasurement of cardiac output

Measurement of cardiac output

Ch o lle y B e t al

He m o d y n am ic m o n ito rin g u sin g

e ch o card io grap h y in th e

critically ill

Ed s: De Backe r e t al

Sp rin ge r 2 0 1 1

Hu n tsm an e t al.

Circu latio n 1 9 8 3

Ech o vs Th e rm o d ilu tio n CO m e asu re m e n ts

Le wis JA e t al.

Circu latio n 1 9 8 4

Th e rm o d ilu tio n vs e ch o ( stro ke vo lu m e )

In ter-o bserver variability

Le wis JA e t al.

Circu latio n 1 9 8 4

N = 3 9

CO with echocardiography

Th e p ro s:

• Re liable

• Ad d itio n al m easu rem en ts

(p re ssu re / vo lu m e s)

• Fu ll card iac e valu atio n

• Me asu re m e n t o f SVV

Th e co n s:

• Skills re qu ire d

• Tim e co n su m in g

• In te rm itte n t

PiCCO2®

EV-1000/VolumeViewTM

LiDCOplusTM

Geisen M, et al. Curr Opin Crit Care 2012, 18:377–384

VigileoTM

LiDCOrapidTM

Geisen M, et al. Curr Opin Crit Care 2012, 18:377–384

NICOM®

Nexfin® NICO®ECOM®

Geisen M, et al. Curr Opin Crit Care 2012, 18:377–384

Intermittent Continuous Invasive Limitations Additional

information

PAC + +

(5 -12 min)

+++ Well

described

complication

s

PAP, PCWP,

SVO2

PiCCO + +

(3 sec)

+(+) Specific

arterial

catheter

GEDV,

EVLW, SVV

LiDCO + + + Lithium

injection

SVV

Flotrac +

(20 sec)

(+) SVV

SPONTANEOUS VENTILATION

Inspiration Expiration

- 8 mmHg -2 mmHg

INTRATHORACIC PRESSURE

Effects of Different Ventilatory Modes on

Cardiopulmonary Performance

SPONT. Ass Part. AssTotMofied from

Synder 1984

Pappl

PalvPcp

RH LHITP

abdominal

pressure gut

Pcp

Effects of the increase in ITP : RV pre-load

Pra

Pms

V

R

Pms= driving pressure to the RA

• Changes in ITP will not alter

the (RV afterload) pressure

gradient

• Decrease in VR are due to

increase in Pra because of

increased in pericardial

pressureIncrease in

Pericardial Pressure

LHRH

effects of changes in ITP: LV afterload

PalvPcp

RH LHITP

abdominal

pressure gut

Pcp

Pappl

spontaneous

breath

mechanical

breath

RH LH

effects of changes in ITP: LV afterload

PalvPcp

RH ITP

abdominal

pressure gut

Pcp

Pappl

spontaneous

breath

mechanical

breath

LH

CPAP IN CARDIOGENIC

PULMONARY EDEMA

Rasen et al: Chest 1985; 87: 158-162

EFFECTS OF LUNG VOLUME CHANGES

LOW LUNG

VOLUME

HIGH LUNG

VOLUME

Pappl

PalvPcp

RH LHITP

abdominal

pressure gut

Pcp

• Incresase in PAP

afterload is due to

increase in PA resistance

•Decrease in VR are due

to increase in Pra

because of increased PA

resistance

Effects of the increase in lung volume: RV afterload

and preload

Pra

Pms

V

R

RH LH

EFFECTS OF POSITIVE

INTRATHORACIC PRESSURE

ON VENOUS RETURN

Pulmonary compliance HIGH

(Emphisema)

LOW (ARDS)

Chest wall compliance HIGH

LOW

TAKE HOME MESSAGE

Chest ultrasound in

Acute Respiratory Distress SyndromeCorradi F., Brusasco C., Pelosi P. Curr Opin Crit Care 2014, 20:98–103

Pelosi P., Corradi F. Anesthesiology 117(4):696-698, 2012

Known Variations to Indexes at the Bedside

Biais, Anesthesiology 2012

Why use these Dynamic Indexes?

MECHANICAL VENTILATION

RA RVLV

LA

LUNGS

PA

AOVenous Return

INSPIRATION

C

H

E

S

T

MECHANICAL VENTILATION

RARV

LVLA

LUNGSPA

AOVenous Return

EXPIRATION

C

H

E

S

T

Overall Picture - Inspiration

Broccard, J Clin Monit Comput 2012

Overall Picture - Expiration

Broccard, J Clin Monit Comput 2012

Assessing Fluid Responsiveness by the

Systolic Pressure Variation in Mechanically

Ventilated Patients

Perel A. Anesthesiology 1998

Looking back in 80’s…

Szold, Intensive Care Med 1989

Predict who could be responsive

to volume restoration

P sys MAX

P sys MIN

SV MAXSV MAX

PP MAX

PP MIN

SV = K • A

STROKE VOLUME VARIATION

SVmax – SVmin

SVV =

SVmean

Which Parameter can better recognize it?

+ -+

-

SVV > 10%

SVV < 10%

+ -+

-

PPV > 15%

PPV < 15%

Michard, Chest 2002

Which Parameter can better recognize it?

Michard, Chest 2002

LOW HIGHMEDIUM

R I S K

Pulse oximeter / capnometry

Plethysmography variability

Arterial catheter / PPV

Pulse contour CO

PAC

ScvO2

Transesophageal Doppler

Indicator dilution CO

Limitations of functional hemodynamic parameters

- Spontaneous breathing

- Tidal volume should be 8 ml/kg

- Nonstandardized airway pressure/respiratory rate

- Open-chest conditions may affect the FHP

- Pediatric patients

- Nonsinus rithm

- Right heart failure

PPV/SVV – Dynamic Arterial ElastanceP

ress

ure

Volume

PPV=18.6%

PPV=27%

PPV/SVV=1.03

Eadyn

PPV/SVV=1.5

Eadyn’

Giraud, Crit Care 2011

Cuttoff

Values?

Monge-Garcia, Crit Care 2011

PPV/SVV – Dynamic Arterial Elastance

0,89

Arterial catheter

Central venous catheter

Fluid Responsiveness

(FHP – CVP)

ECHO

present

Hypovolemia likely

Fluid challange

absent

Small chambers

Poor contractile state

Valvulopathy

(cardiogenic)

RV dilatation

Tamponade

Physiological background

SatvO2= SataO2 -VO2 (mL/min)

Q (L/min)

1

Hb (gr/L) * 1.39*

SatvO2 = metabolism

hemodynamic

1

carrier*Lung -

Venous PO2

PvCO2

SatvO2

Base excessv

Reflects the tissue oxygenation

Reflects

Assessment of metabolic status

(always different from the

arterial)

Venous blood

the arterial PaCO2

the tissue acidosis

Reflects SataO2, VO2/Q, Hb

Venous-arterial sampling

It allows

The shunt computation

a-vO2 difference

(Sata – Satv)/Sata

PCO2

PCO2/a-vO2 content

LACTATE !

Venous-Arterial blood gases allow to:

Define the oxygenation status

(PaO2-Shunt (not replaceable))

Define the ventilatory status

Infere on the hemodynamic status

(a-vO2, SatvO2, (SataO2 – SatvO2)/SataO2 (not

replaceable))

Define the energy failure – BE, pH, PCO2/a-vO2

HIGH LOW

SVO2

HIGH

HIGH LOW

SVO2

LOW

CO

Diagnostic process

Heart failure ( PAOP)

Hypovolemia ( PAOP)

Obstruction ( PAP)

Hyperd. States

vasoact agents

Hypervolemia

Hypoxiemia (SaO2 )

Anemia (SaO2 = V02 =)

Exercise (SaO2 = V02 )

Low anesthesia level

Stress (SaO2 = V02 )

Deep anaesthesia

(V02 )

Hypothermia V02 )

Sepsi ( V02 )

SVO2 = SaO2 – VO2/Q * 1/(1.36*Hb) Fick equation

SVO2 = LUNG - METABOLISM/HEMODYNAMIC * 1/ANEMIA

Conclusions

Preload, flow and flow adequacy

Non invasive and Invasive methods

(Echo and other Methods)

Ventilatory assist affects hemodynamics

Flow adequacy: consider ScvO2 and

Lactate